To produce target products, e.g., L-amino acids, organic acids, or nucleic acid materials, with high yield by using microorganisms, there is a need to selectively control the expression of genes related to a number of metabolic processes in the microorganisms. In particular, there is a need to enhance the expression of target genes involved in a biosynthetic pathway of the target products, and for example, a modification of an expression regulatory sequence may be performed. Such a modification of the expression regulatory sequence may include, for example, a substitution a native promoter for a strong promoter, a modification of a native promoter, or a modification of a Shine-Dalgarno (SD) sequence. The substitution a native promoter for a strong promoter has been used the most, and in this regard, it is considered essential to develop a useful promoter.
However, strong promoters known in the art are limited, and may be expressed only in a limited microorganism. In some cases, the strong promoters may fail to exhibit strong expression effects at various intensity levels as desired.
A tac promoter derived from Escherichia coli is widely known as a strong promoter in the art. In the case of the genus Corynebacterium, a new promoter has been developed by modification of a native promoter (see Gene, 102, 93-98, 1991; Microbiology, 142, 1297-1309, 1996). For example, it was reported that a promoter derived from Corynebacterium ammoniagenesis had about 10% higher activity than that of the tac promoter derived from E. coli (see Biotechnol. Lett. 25, 1311-1316, 2003). In addition, as a strong promoter derived from Corynebacterium ammoniagenesis, promoters of Pcj1 to Pcj7 with various intensity levels have been developed and had strong promoter activity that is at least 10 times as large as that of the tac promoter (see KR 10-0620092). In addition, a promoter derived from Brevibacterium flavum MJ-233 (FERM BP-1497) was reported to have a stronger activity than that of the tac promoter, but had a difficulty in its expression in a microorganism other than a microorganism belonging to the genus Brevibacterium (see U.S. Pat. No. 5,593,781).
In this regard, when the inventors of the present inventive concept explore a region including a promoter sequence that can have various intensity levels in a variety of different microorganisms, a novel promoter synthesized according to the present inventive concept is found to be expressed in a variety of different microorganisms and to exhibit much stronger expression effects than those of the existing promoters known in the art, thereby completing the present inventive concept.